# The graph between the resistive force F acting on a body and the distance covered by the body is shown is shown in the figure. The mass of the body is 60 kg and the initial velocity is 3m/s. When the distance covered by the body is 4m, its kinetic energy will be  Option 1) 250 J Option 2) 230 J Option 3) 200 J Option 4) 220 J

As we learnt in

Kinetic energy -

$k= \frac{1}{2}mv^{2}$

- wherein

$m\rightarrow mass$

$v\rightarrow velocity$

kinetic Energy is never negative

$K=\frac{1}{2}mV^{2}$$=\frac{1}{2}\times60\times3^{2}$$=\frac{1}{2}\times60\times9$

$K=\frac{540}{2}$$=270 J$

Work done against resistance force = Area between F-x graph  $=\frac{1}{2}\times 4\times 20=40 J$

$\therefore$    Final K.E. = 270 - 40 = 230 J

Option 1)

250 J

Incorrect

Option 2)

230 J

Correct

Option 3)

200 J

Incorrect

Option 4)

220 J

Incorrect

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